Field
The methods and apparatus described herein relate generally to the field of restorative dentistry. The methods and apparatus relate more specifically to the extremely rapid fabrication of ceramic (e.g., zirconia, lithium silicate, lithium disilicate) dental restorations to permit preparation of, for example, zirconia, lithium silicate, or lithium disilicate crowns, bridges, or other restorations in a dental office during a single visit by a patient.
Background Discussion
There are several important advantages to ceramic dental restorations, including zirconia, lithium silicate, and lithium disilicate dental restorations that make them ideal material for use as dental crowns, bridges and the like. First, they are very strong and therefore highly resistant to chipping, breakage and wear. For example, the assignee hereof has achieved a flexure strength exceeding 1600 MPa in monolithic zirconia crowns. Second, they can be shaped, sized and colored to take on a natural appearance that is essentially undistinguishable from the original teeth they restore or replace. Third, they can be fabricated in a manner which results in a cost effective restoration when compared to conventional materials such as PFM.
There is yet another potential fourth advantage which has not been fully realized in the dental restoration art. This advantage would, if achievable, result from the qualities of a monolithic ceramic material, including zirconia, lithium silicate, and lithium disilicate, which can be fabricated in distinct steps that need not be accomplished all at one time. This advantage would be realized at the dentist's office where it would significantly reduce the time required to fully fabricate a patient/tooth specific finished restoration within a time period so short that it can be conveniently accomplished while the patient is in the dental office and even while in the dental chair. Such time periods to be practical would have to be one hour or less, including the time a patient first sits in a dental chair to be examined for a new crown and until that same patient exits the dental chair with a newly installed crown. And not just any standard crown, but, in some embodiments, one that is stronger, equal to, or better than the natural tooth in appearance and reasonably priced, or even less costly than conventional crowns. Such an invention could realistically change a significant part of the dental profession and the dental laboratory industry.